chromium/third_party/blink/web_tests/media/controls-css-overload.html

<!DOCTYPE html>
<title>Testing that overloading some controls doesn't crash the browser</title>
<script src="../resources/testharness.js"></script>
<script src="../resources/testharnessreport.js"></script>
<style>
    .nocontrols::-webkit-media-controls-panel {
        display:none;
    }
    .notimeline::-webkit-media-controls-timeline-container {
        display:none;
    }
</style>
<video class="nocontrols" width=300 height=200 controls></video>
<video class="notimeline" width=300 height=200 controls></video>
<script>
test(function() {
    // Test is complete if there is no crash.
});
</script>
</body>
</html>